OS X: Fix dynamically generated context menus, such as the sort by menu not working: Fixes #1652694 [Empty Sort By List in Cover Grid Context Menu](https://bugs.launchpad.net/calibre/+bug/1652694)

src/calibre/gui2/actions/sort.py

@@ -38,6 +38,7 @@ class SortByAction(InterfaceAction):
 
     def genesis(self):
         self.sorted_icon = QIcon(I('ok.png'))
+        self.qaction.menu().aboutToShow.connect(self.update_menu)
 
     def location_selected(self, loc):
         self.qaction.setEnabled(loc == 'library')
@@ -76,5 +77,3 @@ def sort_requested(self, key, ascending):
             self.gui.library_view.intelligent_sort(key, True)
         else:
             self.gui.library_view.sort_by_named_field(key, ascending)
-
-

src/calibre/gui2/bars.py

@@ -253,6 +253,7 @@ def clone_changed(self):
 
 # MenuBar {{{
 
+
 if isosx:
     # On OS X we need special handling for the application global menu bar and
     # the context menus, since Qt does not handle dynamic menus or menus in
@@ -273,6 +274,15 @@ def __init__(self, clone, parent, is_top_level=False, clone_shortcuts=True):
             self.clone_changed()
             self.triggered.connect(self.do_trigger)
 
+        def clone_menu(self):
+            m = self.menu()
+            m.clear()
+            for ac in QMenu.actions(self.clone.menu()):
+                if ac.isSeparator():
+                    m.addSeparator()
+                else:
+                    m.addAction(CloneAction(ac, self.parent(), clone_shortcuts=self.clone_shortcuts))
+
         def clone_changed(self):
             otext = self.text()
             self.setText(self.clone.text())
@@ -293,12 +303,17 @@ def clone_changed(self):
                     self.setMenu(None)
             else:
                 m = QMenu(self.text(), self.parent())
-                for ac in QMenu.actions(self.clone.menu()):
-                    if ac.isSeparator():
-                        m.addSeparator()
-                    else:
-                        m.addAction(CloneAction(ac, self.parent(), clone_shortcuts=self.clone_shortcuts))
+                m.aboutToShow.connect(self.about_to_show)
                 self.setMenu(m)
+                self.clone_menu()
+
+        def about_to_show(self):
+            cm = self.clone.menu()
+            before = list(QMenu.actions(cm))
+            cm.aboutToShow.emit()
+            after = list(QMenu.actions(cm))
+            if before != after:
+                self.clone_menu()
 
         def do_trigger(self, checked=False):
             if not sip.isdeleted(self.clone):
@@ -553,5 +568,3 @@ def apply_settings(self):
             bar.setToolButtonStyle(style)
         self.donate_button.setIconSize(bar.iconSize())
         self.donate_button.setToolButtonStyle(style)
-
-

src/calibre/gui2/library/alternate_views.py

@@ -932,10 +932,6 @@ def contextMenuEvent(self, event):
         if self.context_menu is None:
             return
         from calibre.gui2.main_window import clone_menu
-        sac = self.gui.iactions['Sort By']
-        sort_added = tuple(ac for ac in self.context_menu.actions() if ac is sac.qaction)
-        if sort_added:
-            sac.update_menu()
         m = clone_menu(self.context_menu) if islinux else self.context_menu
         m.popup(event.globalPos())
         event.accept()

src/calibre/gui2/library/views.py

@@ -840,10 +840,6 @@ def set_context_menu(self, menu, edit_collections_action):
 
     def contextMenuEvent(self, event):
         from calibre.gui2.main_window import clone_menu
-        sac = self.gui.iactions['Sort By']
-        sort_added = tuple(ac for ac in self.context_menu.actions() if ac is sac.qaction)
-        if sort_added:
-            sac.update_menu()
         m = clone_menu(self.context_menu) if islinux else self.context_menu
         m.popup(event.globalPos())
         event.accept()

src/calibre/gui2/main_window.py

@@ -170,6 +170,7 @@ def clone_menu(menu):
     # This is needed to workaround a bug in Qt 5.5+ and Unity. When the same
     # QAction object is used in both a QMenuBar and a QMenu, sub-menus of the
     # QMenu flicker when rendered under Unity.
+
     def clone_action(ac, parent):
         if ac.isSeparator():
             ans = QAction(parent)